When unmount the pak file with m.ubulk on ue4.26.2, it gonna shutdown app

Operating System : iOS 15.6

Engine Version : 4.26.2

Paked file : audio file with wav extension

Hi~

I have some issue with pak file. The pak file is a cooked audio resource and it is loaded as m.ubulk extension. The files be added to loading step, and precacher mount it in game. And after a while, unmount is ordered, and at this time, the NumOutstandingRegions value in the ~FIOSMappedFileHandle() function is greater than zero, causing a problem. The problem is that MapRegion has not been released, it seems normal that MapRegion is not released. Please point out if there is anything I don’t know.

Thanks to read this